Need a nutritious lunch, fast?

Nutritionist Dawn Jackson Blatner found a long list of healthful, low-sodium soups at Au Bon Pain; add a roll or side salad with fat-free raspberry vinaigrette. Photo: Todd Winters

Say lunchtime means grabbing something to eat at your desk  pretty much every day. Is it possible to avoid super-sizing yourself?

Dawn Jackson Blatner isn't sure. "People who do well with weight control may dine out two or three times a week  total," says Ms. Blatner, a registered dietitian at Northwestern Memorial Hospital's Wellness Institute.

She looked over the menus of 10 fast-food and fast-casual chains, matching their nutrition information (available online) against her general standards. Surprisingly, Wendy's, McDonald's and KFC came out ahead of Cosi, Corner Bakery and Chipotle.

Ms. Blatner used three main criteria for a healthy lunch: It should contain 500 to 700 calories for weight control, total fat should be under 20 grams and sodium less than 1,000 milligrams, in line with federal guidelines.

In the end, Ms. Blatner found lunch options at almost every spot. But it was striking how many options that fit one profile  low-calorie or low-sodium or low-fat  are eliminated when you try to achieve the right levels in more than one category.

Subway

Only oven-roasted chicken, roast beef, savory turkey or a veggie sandwich, without pickles, olives or hot peppers, all of which are sodium bombs. Have mustard, mayo or natural cheddar cheese. Vinegar and oil are okay.

Corner Bakery

"Avoid it for lunch," Ms. Blatner says. The only options: a small Southwest corn chowder with fruit salad or a side-salad combo, as long as one of them is potato dill or fruit medley.

Au Bon Pain

"The best low-sodium soups I can find anyplace  some soups are just about 200 milligrams. It's crazy!" Have soup with a roll or side salad with fat-free raspberry vinaigrette dressing. For entree salads: chicken Caesar and Thai chicken salads, only with fat-free dressing. Only one sandwich: the fields and feta wrap.

Cosi

On salty flatbread, "all of their sandwiches are too high in sodium for me to recommend." Cobb and Florentine salads break the sodium ceiling, while the signature salad has too much fat. Other salads are fine, using fat-free balsamic vinaigrette or reduced-fat shallot-sherry dressing. So are small servings of three-bean chili or chicken noodle soup.

KFC

Chicken breast, no skin, with a small corn on the cob, a serving of mashed potatoes with gravy and applesauce for dessert. "It's actually a pretty well-rounded meal."

Chipotle

"When I try to put a burrito bowl together, I can't put together one within the recommended sodium levels."

McDonald's

Ms. Blatner actually sends patients here, recommending a cheeseburger (260 calories, 9 grams of fat, 530 milligrams of sodium) and Apple Dippers. Or a hamburger and, yes, a small order of fries. Or a grilled chicken sandwich, solo. Many salads are fine, although you generally have to choose between adding grilled chicken or applying salad dressing. Add a fruit and yogurt parfait, especially if you leave off the granola.

Panda Express

No combos; steamed rice only. Do that, and you can add a spring roll to any of seven entrees: Chicken with mushrooms, black pepper chicken, chicken with string beans, sweet and sour chicken, beef with broccoli, beef with string beans or string beans with fried tofu.

Wendy's

"A baked potato with a small chili is a great idea, and very filling," Ms. Blatner says. "And if you're looking for more, you can always add a fresh fruit with yogurt." Or have a junior burger and side salad with fat-free French or low-fat honey-mustard dressing.

Potbelly Sandwich Works

Big points for offering "skinny" versions of its sandwiches  through the low-tech means of cutting away some of the bread. "That is so cool! People pooh-pooh that, but small changes can make a huge difference." Even the not-so-skinny sandwiches are reasonably low in fat. But there's a catch: "Lunch meats are salty little guys." Only the skinny roast beef and pizza with provolone come in below 1,000 milligrams.